Born in New York City, Frank Schlesinger earned his B.S. in 1890 at the College of the City of New York and his Ph.D. in 1898 at Columbia University. After three and one-half years measuring variations in latitude in Ukiah, California, he was hired by Yerkes Observatory, where, with the encouragement of director George E. Hale, he pioneered in the use of photographic techniques to determine stellar parallaxes. He soon showed that photographic methods could give more precise results than visual ones, and with less than one hundredth as much time at the telescope. Schlesinger served as director of Allegheny Observatory from 1905 to 1920 and of the Yale University Observatory from 1920 to 1941. He designed instruments and mathematical and numerical techniques to improve parallax measurements. He published ten volumes of zone catalogs, including some 150,000 stars. He compiled positions, magnitudes, proper motions, radial velocities, and other data to produce the first edition and, with Louise Jenkins, the second, of the widely-used Bright Star Catalogues, making Yale a leading institution in astrometry. He also did spectroscopic work, determining orbits of spectroscopic binary stars. He established a second Yale observatory in South Africa and personally supervised its construction. He was an influential leader in the astronomical community and held several offices, including president, in both the American Astronomical Society and the International Astronomical Union.